Checking High-Voltage Capacitor A4 For Grounding; Diode V1 Test; Figure 012-12: Diode V1 Test Circuit - Miele H 408 BM Series Technical Information

H 408x BM
4.15

Checking High-Voltage Capacitor A4 for Grounding

1. Remove the appliance from its cabinet; see Section 011-4.3.
2. Remove the screws securing the appliance lid. Remove the lid.
Danger!
Before performing any service or repair work, discharge the high-voltage
capacitor. See Section A-2.
3. Pull both connectors off the high-voltage capacitor.
4. Measure the resistance between one terminal and the metal housing of
the capacitor. This measured value must be infinite ∞.
5. Repeat the measurement for the second terminal.
Danger!
After installation/repair is completed, as a matter of standard practice, the
appliance has to be checked for a tight seal with a microwave leak detector,
paying particular attention to the door and the housing edges.
4.16

Diode V1 Test

1. Remove the appliance from its cabinet; see Section 011-4.3.
2. Remove the screws securing the appliance lid. Remove the lid.
Danger!
Before performing any service or repair work, discharge the high-voltage
capacitor. See Section A-2.
3. Remove the diode (assembly) from the appliance.
4. Connect the V1 diode in series on the positive lead between a 9-volt
battery and a voltmeter, as shown in Figure 012-12, Item A. A properly
functioning diode should provide a voltage of about 4.5 to 6.5 volts DC
(depending on the condition of the battery).
5. Reverse the position of the diode. Connect the V1 diode in series on the
positive lead between a 9-volt battery and a voltmeter, as shown in Figure
012-12, Item B. A properly functioning diode should not allow voltage to
pass through the circuit when placed in this position. The voltmeter
should display 0.

Figure 012-12: Diode V1 Test Circuit

Danger!
After installation/repair is
completed, as a matter of
standard practice, the
appliance has to be checked
for a tight seal with a
microwave leak detector,
paying particular attention to
the door and the housing
edges.
39
Technical Information